Binaural and top-down mechanisms in auditory scene analysis

摘要 在我们正常的忙碌生活中，我们很少听到孤立的声音。在大多数情况下，例如鸡尾酒会，许多 声源是存在的，并且它们的波形在听者的耳朵处简单地加在一起;所有听者 听觉是单一复合波形。值得注意的是，听众能够分解这种复杂的波形， 通过频率和其他线索将这些成分分离出来，并将它们组合在一起，形成一个连贯的概念 这个过程通常被称为“听觉场景分析”。助听器和 耳蜗植入物用户在该过程中特别困难， 存在声源。更好地理解听觉场景分析的机制可能 解决其中一些困难。听觉场景分析是一个利用声音特征的过程 （自下而上处理）和听众的期望（自上而下处理）。的长期目标 这项研究的目的是了解自下而上的加工机制，以及它如何与 自上而下的处理。 拟议的研究旨在了解双耳机制的生理学，用于提取单个 来自具有多个声源的环境的声音。听觉系统可以比较和对比 输入的两个耳朵，并使用这些双耳线索分离的声音。人们对这一点知之甚少。 当存在多种声音时比较双耳输入的生理过程。这种缺乏 知识已经成为进一步提高助听器或人工耳蜗患者听力的障碍。 两个耳朵都有植入物拟议研究的一个目的是确定用于 当存在多个声源时提取单个声音。本提案将使用多个 复杂的声音（谐波复合），以识别用于分离声音的双耳神经机制。 拟议研究的第二个目的是确定自上而下的过程如何影响双耳 用于分离声音的机制。拟议的研究将联合收割机电生理学在下 听觉皮层失活技术，以确定双耳之间的相互作用 机制和自上而下的处理。结果将提供一个框架，双耳优势， 复杂的环境可能有助于最大限度地发挥双侧助听器和双侧助听器的益处。 人工耳蜗植入物。

ABSTRACT In our normal busy lives we rarely hear isolated sounds. In most situations, such as a cocktail party, many sound sources are present and their waveforms simply add together at the listener's ears; all that listeners hear is a single complex waveform. Remarkably, listeners are able to break down this complex waveform, segregate the components by frequency and other cues, and group them together to form a coherent percept of the separate sources; this process is commonly referred to as "auditory scene analysis". Hearing aid and cochlear implant users have particular difficulty with this process and many avoid environments where multiple sound sources are present. A better understanding of the mechanisms underlying auditory scene analysis may solve some of these difficulties. Auditory scene analysis is a process that utilizes the features of the sound (bottom-up processing) and the expectations of the listener (top-down processing). The long-term objective of the proposed research is to understand the mechanisms of the bottom-up processing and how it interacts with the top-down processing. The proposed research aims to understand the physiology of the binaural mechanisms used to extract a single sound from an environment with multiple sound sources. The auditory system can compare and contrast the input of the two ears and use these binaural cues to segregate sounds. Little is understood about the physiological processes that compare the input of the two ears when multiple sounds are present. This lack of knowledge has become a barrier to further improving the hearing of people with hearing aids or cochlear implants in both ears. One aim of the proposed research is to determine the binaural mechanisms used in extracting a single sound when multiple sound sources are present. The present proposal will use multiple complex sounds (harmonic complexes) to identify the binaural neural mechanisms used to segregate sounds. The second aim of the proposed research is to determine how top-down processes affect the binaural mechanisms used to segregate sounds. The proposed research will combine electrophysiology in the inferior colliculus with auditory cortical inactivation techniques to determine the interaction between binaural mechanisms and top-down processing. The results will provide a framework for binaural advantages in complex environments that may help with maximizing the benefit from bilateral hearing aids and bilateral cochlear implants.